Air conditioner

ABSTRACT

Provided is an air conditioner. The air conditioner includes a mechanical chamber receiving a compressor for compressing a refrigerant and a water-cooled heat exchanger for heat-exchanging water introduced from the outside and flowing along a water pipe with the refrigerant, an air-cooled heat exchanger disposed on a top surface of the mechanical chamber, the air-cooled heat exchanger being fluidly connected to the compressor, and a fan disposed above the air-cooled heat exchanger. A refrigerant pipe constituting the air-cooled heat exchanger is bent several times along an outer edge of the fan and has a polygonal pillar shape extending in a vertical direction.

TECHNICAL FIELD

The present disclosure relates to an air conditioner.

BACKGROUND ART

In general, air conditioning systems are systems in which indoor air is cooled or heated using a refrigerant circulation cycle including compression, condensation, expansion, and evaporation processes which are successively performed.

In a general refrigerant circulation cycle, a compressor, a condenser, an expansion member, and an evaporator are connected by refrigerant pipes to realize a closed circuit. Also, a refrigerant is heat-exchanged with air in the condenser and evaporator. That is, the refrigerant within the condenser decreases in temperature due to the heat exchange between the air and the refrigerant. Also, the refrigerant within the evaporator increases in temperature due to the heat exchange between the air and the refrigerant. Also, air cooled through the heat exchange in the evaporator may be supplied into an indoor space, and air heated through the heat exchange in the condenser may be supplied into the indoor space.

Air conditioning systems that are water-cooled heat exchangers has been developed in recent years so that a refrigerant within one of the condenser and the evaporator is not heat-exchanged with air, but is heat-exchanged with other fluids, e.g., water. In detail, in one heat exchanger serving as a condenser or evaporator, refrigerant and water are not mixed with each other, but are heat-exchanged with each other.

In case of combination type air conditioning systems including an air-cooled heat exchanger and water-cooled heat exchanger, the air-cooled heat exchanger is installed in an outdoor space and other system components except the air cooled heat exchanger are received in a separate case and then installed in an indoor space. Alternatively, the air cooled heat exchanger and the case may be provided as one module and then installed in the outdoor space.

FIG. 1 is a perspective view of an air conditioning system according to a related art.

Referring to FIG. 1, an air conditioning system according to a related art includes a case 2 receiving a compressor, a four-way valve, a water-cooled heat exchanger, and an expansion member, an air-cooled heat exchanger 3 installed on a top surface of the case 2, and a fan assembly 4 for forcibly blowing air to heat-exchange the air-cooled heat exchanger 3 with air.

In detail, when the air conditioning system 1 is operated as a heat pump, the air-cooled heat exchanger 3 may serve as a condenser in which a high-temperature high-pressure refrigerant flows. Also, when the air conditioning system 1 is operated as a cooler, the air-cooled heat exchanger 3 may serve as an evaporator in which a low-temperature low-pressure two-phase refrigerant flows.

Also, the air-cooled heat exchanger 3 may have a V shape as shown in FIG. 1.

However, when the air-cooled heat exchanger 3 has the V shape, there is a limitation to increase a heat exchange area of the heat exchanger under a limited condition in a plane area of the case 2, i.e., a bottom area of the heat exchanger.

In addition, when two (or more) fan assemblies 4 are installed on an upper end of the V-shaped heat exchanger as shown in FIG. 1, heat exchange efficiency may be significantly reduced in case where one of the plurality of fans may be broken down.

In detail, when a portion of the fans is broken down in the existing V-shaped heat exchanger, air existing in an outer upper side of the broken fan and air existing in a lower space of the broken fan within an inner space of the heat exchanger may flow toward the normal operating fan. As a result, air existing outside a side surface of the heat exchanger does not flow into the inner space of the heat exchanger. That is, the amount of air flowing by one normal fan may be reduced than the amount of air flowing by two normal fans. Furthermore, the amount of air sucked from the outside of the heat exchanger may be reduced. That is to say, the amount of air existing inside the V-shaped heat exchanger in air sucked by the normal operating fan may be greater than the amount of air sucked from the heat exchanger. This is done because the air sucked from the outside of the heat exchanger is affected by a flow resistance due to fins of the heat exchanger. However, air within the heat exchanger is not affected by the flow resistance.

Thus, there is a limitation that the heat exchange is not smoothly performed in a heat exchanger region that should be covered by the normal operating fan as well as a heat exchanger region covered when the broken fan is normally operated.

DISCLOSURE OF INVENTION Technical Problem

Embodiments provide an air conditioning system in which a heat exchanger is improved in shape to maximally secure a heat exchange area in comparison to a single bottom area.

Embodiments also provide an air conditioning system in which only a heat exchange function in a heat exchange region covered by a broken fan assembly is stopped, and a heat exchange function in a heat exchange region covered by a normal operating fan is not affected by the broken fan assembly to realize normal heat exchange efficiency.

Solution to Problem

In one embodiment, an air conditioner includes: a mechanical chamber receiving a compressor for compressing a refrigerant and a water-cooled heat exchanger for heat-exchanging water introduced from the outside and flowing along a water pipe with the refrigerant; an air-cooled heat exchanger disposed on a top surface of the mechanical chamber, the air-cooled heat exchanger being fluidly connected to the compressor; and a fan disposed above the air-cooled heat exchanger, wherein a refrigerant pipe constituting the air-cooled heat exchanger is bent several times along an outer edge of the fan and has a polygonal pillar shape extending in a vertical direction.

In another embodiment, an air conditioner includes: a mechanical chamber receiving a compressor for compressing a refrigerant and a water-cooled heat exchanger for heat-exchanging water introduced from the outside and flowing along a water pipe with the refrigerant; an air-cooled heat exchanger disposed on a top surface of the mechanical chamber, the air-cooled heat exchanger including a plurality of heat exchange parts; and a fan disposed above the air-cooled heat exchanger, wherein the plurality of heat exchange parts include: a first heat exchange part including one bent part; and a second heat exchange part coupled to the first heat exchange part, the second heat exchange part including the other bent part, wherein the air-cooled heat exchanger has a polygonal box shape due to the coupling of the first heat exchange part and the second heat exchange part.

Advantageous Effects of Invention

The air conditioner including the above-described constitutions may realize effects as follows.

First, even though one of the plurality of fan assemblies installed in the heat exchanger is broken down, heat exchange performance in the heat exchange region defined at a side of the other normal operating fan assembly is not affected by the broken fan assembly.

Second, since the heat exchanger has the polygonal box (column) shape, the distance from the center of the fan assembly up to the heat exchanger in a circumference direction is constant from an upper end of the heat exchanger up to a lower end. Therefore the uniform flow rate may be secured in the whole heat exchanger.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an air conditioning system according to a related art.

FIG. 2 is a perspective view illustrating an outer appearance of an air conditioning system according to an embodiment.

FIG. 3 is a view illustrating constitutions of the air conditioning system.

FIG. 4 is a plan view illustrating a set of a fan and heat exchanger according to a first embodiment.

FIG. 5 is a view illustrating constitutions of a heat exchange part according to the first embodiment.

FIG. 6 is a plan view illustrating a set of a fan and heat exchanger according to a second embodiment.

MODE FOR THE INVENTION

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, that alternate embodiments included in other retrogressive inventions or falling within the spirit and scope of the present disclosure will fully convey the concept of the invention to those skilled in the art.

FIG. 2 is a perspective view illustrating an outer appearance of an air conditioning system according to an embodiment. FIG. 3 is a view illustrating constitutions of the air conditioning system.

Referring to FIGS. 2 and 3, an air conditioning system according to an embodiment is a combination-type system in which a water-cooled heat exchanger and an air-cooled heat exchanger are used together with each other. That is, the air conditioning system may heat or cool indoor air using water cooled or heated by heat-exchanging with a refrigerant used in a refrigeration cycle or may be used for providing cool and warm water.

In detail, the air conditioning system 10 according to the current embodiment includes a case 101 for receiving components used for the refrigeration cycle and an air-cooled heat exchanger 15 disposed outside of the case 101, i.e., a top surface of the case 101. Also, the components constituting the air conditioning system 10 are connected to each other by refrigerant pipes 16 to realize a closed circuit.

In more detail, the air conditioning system 10 includes a compressor for compressing the refrigerant at a high-temperature high-pressure, a four-way valve 12 disposed at an outlet side of the compressor 11 to convert a flow direction of the refrigerant, a water-cooled heat exchanger 13 connected to one of outlets of the four-way valve 12, an expansion member 14 connected to an outlet side of the water-cooled heat exchanger 13, and an air-cooled heat exchanger 15 connected to an outlet side of the expansion member 14.

An outlet end of the air-cooled heat exchanger 15 is connected to the other one of the outlets of the four-way valve 12. Also, a water utilizer 20 using water as an operation fluid is connected to the water-cooled heat exchanger 13 by a water pipe 17. The water utilizer 20 may include an air conditioner installed in an indoor space to cool or heat indoor air or an indoor bottom or a hot/cold water dispenser for supplying cold and hot water.

Also, the four-way valve 12 may be disposed on the outlet side of the compressor 11 so that a high-temperature high-pressure refrigerant discharged from the compressor 11 flows toward one of the water-cooled heat exchanger 13 and the air-cooled heat exchanger 15 according to an operation mode.

A fan 151 is disposed on a side of the air-cooled heat exchanger 15 to heat-exchange external air with a refrigerant flowing into the air-cooled heat exchanger 15. Here, a heat exchange assembly constituted by the air-cooled heat exchanger 15 and the fan 151 may be disposed outside the case 101, and other components except the water utilizer may be received into the case 101. The heat exchanger assembly may be provided in plurality on the case 101.

Also, the water-cooled heat exchanger 13 may have a structure in which only the heat exchange is performed without mixing the refrigerant circulating the refrigerant circulation cycle and the water flowing along the water pipe 17. For example, a plate-type heat exchanger well known in the related art may be used as the water-cooled heat exchanger 13. Also, as shown in FIG. 2, a chiller in which a refrigerant is introduced into a cylindrical case and a water pipe meanderingly bent in several times in an S shape within the cylindrical case is received may be used as the water-cooled heat exchanger. In detail, the water pipe is received into the case of the chiller and a refrigerant is filled into the case of the chiller. Thus, water flowing along the inside of the water pipe is heat-exchanged with the refrigerant filled into the case of the chiller without being mixed with the refrigerant.

In detail, a refrigerant suction port 13 a may be disposed on one side of the chiller, and a refrigerant discharge port 13 b may be disposed on the other side of the chiller. A refrigerant pipe extending from the four-way valve 12 is connected to the refrigerant suction port 13 a. The refrigerant discharge port 13 b is connected to an inlet of the expansion member 14 by the refrigerant pipe.

Also, a high-temperature high-pressure refrigerant discharged from the compressor 11 may be supplied into the water-cooled heat exchanger 13 or a low-temperature low-pressure two-phase refrigerant discharged from the expansion member 14 may be supplied into the water-cooled heat exchanger 13 according to a state of the four-way valve 12.

Here, a flow direction of the refrigerant may be decided according to the converted state of the four-way valve 12. For example, a flow of the refrigerant when the air conditioning system 10 performs a heating cycle operation such as a heat pump is as follows.

In detail, a flow direction of a supersaturated gaseous refrigerant compressed at a high-temperature high-pressure by the compressor 11 is decided by the four-way valve 12 to flow into the water-cooled heat exchanger 13. Also, the refrigerant passing through the water-cooled heat exchanger 13 may be changed in phase into a two-phase refrigerant while passing through the expansion member 14. Also, the refrigerant passing through the expansion member 14 is changed in phase into a low-temperature low-pressure saturation refrigerant while passing through the air-cooled heat exchanger 15. Then, the low-temperature low-pressure saturation refrigerant returns to the compressor 11 via the four-way valve 12. Here, a process in which the refrigerant and the water are heat-exchanged with each other is performed in the water-cooled heat exchanger 13. That is, the water introduced into the water-cooled heat exchanger 13 along the water pipe 17 may absorb heat from the high-temperature high-pressure refrigerant and thus be heated to return to the water utilizer 20. The water utilizer 20 may be used as an indoor heater or a hot water dispenser.

A flow of the refrigerant when the air conditioning system 10 performs a cooling cycle operation such as an air conditioner is as follows.

In detail, a flow direction of a supersaturated gaseous refrigerant compressed at a high-temperature high-pressure by the compressor 11 is decided by the four-way valve 12 to flow into the air-cooled heat exchanger 15. The refrigerant introduced into the air-cooled heat exchanger 15 is heat-exchanged with air and thus changed in phase into a high-temperature high-pressure liquid state. Also, the refrigerant is changed in phase into a low-temperature low-pressure two-phase refrigerant while passing through the expansion member 14. Also, the refrigerant absorbs heat from the water flowing along the water pipe 17 and thus is changed in phase into a low-temperature low-pressure saturation refrigerant while passing through the water-cooled heat exchanger 13. Also, the refrigerant passing through the water-cooled heat exchanger 13 returns to the compressor 11 via the four-way valve 12. Here, heat of the water flowing along the water pipe 17 is lost into the refrigerant and thus cooled. Thus, the water utilizer 20 may be used as a cooler or a cold water dispenser.

As shown in drawings, the air-cooled heat exchanger 15 may have a polygonal pillar shape. Although the air-cooled heat exchanger 15 has a hexagonal pillar shape in the current embodiment, the present disclosure is not limited thereto. For example, the air-cooled heat exchanger may have a polygonal pillar shape including the hexagonal pillar shape as well as a cylindrical shape.

The air-cooled heat exchanger 15 has a box shape. Also, the air-cooled heat exchanger 15 may be constituted by a set of one fan and one heat exchanger having the box shape. Thus, even though one of the plurality of fans is broken down, other normal operating fans and the heat exchange set are not affected by the broken fan. That is, heat exchange efficiency may be reduced in the aspects of the whole heat exchanger. However, the heat exchange may be normally performed in the heat exchanger disposed at a side of the normal operating fan without being affected by the broken fan.

In addition, since the heat exchanger has the box shape, a distance (the shortest distance) from a line vertically extending with respect to a center of the fan up to any position of the heat exchanger may be constantly maintained in a length direction of the heat exchanger. Thus, a uniform flow rate may be secured in the whole heat exchanger.

Hereinafter, a structure of the heat exchanger having a polygonal box shape will be described in detail. For example, a heat exchanger having a hexagonal box shape will be described.

FIG. 4 is a plan view illustrating a set of a fan and heat exchanger according to a first embodiment. FIG. 5 is a view illustrating constitutions of a heat exchange part according to the first embodiment.

Referring to FIGS. 4 and 5, an air-cooled heat exchanger 15 of an air conditioning system according to a first embodiment has a structure in which first and second heat exchanger parts 110 and 120 defined by bending a heat exchanger having a rectangular shape two times are coupled to each other. The first and second heat exchange parts 110 and 120 may be symmetric with respect to each other. Hereinafter, the constitutions of the first heat exchange part 110 will be described. Here, the first and second heat exchange parts 110 and 120 have the same constitution as each other.

The first heat exchange part 110 includes a plurality of main pipes 111 extending in a horizontal direction and spaced a predetermined distance from each other in a vertical direction and ⊂-shaped return bands 112 connecting ends of the main pipes 111 adjacent to each other in a vertical direction to each other. The return bands 114 may be disposed on an end of one side of the main pipe 112 and an end of the other side of the main pipe 112, respectively.

Since the main pipes 111 and the return bands 112 are coupled to each other, the refrigerant pipes constituting the first heat exchange part 110 may be meanderingly connected to each other in an S shape to form a meander line. Also, the refrigerant pipe manufactured by connecting the main pipes 11 to the return bands 112 passes through a plurality of cooling fin 115.

Each of the main pipes 111 includes a plurality of bent parts 113 and 114. In detail, the plurality of bent parts 113 and 114 include a first bent part 113 disposed at one portion of the main pipe 111 and a second bent part 114 disposed at the other portion of the main pipe 114. Since the plurality of bent parts 113 and 114 are provided, the heat exchanger 15 may have a plurality of side surfaces facing a plurality of directions. Thus, air may be heat-exchanged while passing through the plurality of side surfaces.

Although the heat exchanger 15 has the hexagonal box shape to provide the two bent parts in the current embodiment, the present disclosure is not limited thereto. For example, when the heat exchanger 15 has an octagonal box shape, the main pipe 111 may include three bent parts. In summary, the first heat exchanger 110, i.e., the main pipe 111 may include at least two bent parts.

For example, when the main pipe 111 includes two or more bent parts, lines of the polygonal shape may have an angle (see reference symbol a of FIG. 6) less than about 180 degrees with respect to one another.

Also, the return band 112 disposed at one side of the first heat exchange part 110 is disposed adjacent to the return band 120 disposed at one side of the second heat exchange part 120, for example. For example, the two return bands 112 may contact each other. However, the present disclosure is not limited thereto. For example, the two return bands may be disposed more close to each other. Also, the return band 112 disposed at the other side of the first heat exchange part 110 may be disposed more close to the return band disposed at the other side of the second heat exchange part 120.

In summary, the return bands 112 disposed on both side ends of the first heat exchange part 110 and the return bands 112 disposed on both side ends of the second heat exchange part 120 are disposed adjacent to each other. Thus, a horizontal section of the heat exchanger 15 may have a polygonal plane.

Also, since the first and second heat exchange parts 110 and 120 are coupled to each other so that the return band 112 of the first heat exchange part 110 and the return band of the second heat exchange part 120 are more adjacent to each other, an inner region 130 defined by the first and second heat exchange parts 110 and 120 may define a closed space.

Here, the “closed space” may be understood as that the closed space is not opened in side directions and also external air should pass through the heat exchanger 15 to flow into the inner region 130.

As described above, both side ends of the first and second heat exchange parts 110 and 120 are close to each other. Thus, the air-cooled heat exchanger 15 may have a polygonal shape in plane (hexagonal plane in the current embodiment).

That is, in a state where the fan is provided above the heat exchanger 15 and the case 101 is provided under the heat exchanger 15, the side surfaces of the heat exchanger 15 may be closed by the first and second heat exchange parts 110 and 120 including the plurality of bent parts and the return bands adjacent to each other.

Also, as the fan 151 is operated, air may flow from the outside of the air-cooled heat exchanger 15 toward the inside (an arrow direction). Thus, the air is heat-exchanged with the refrigerant within the heat exchanger due to the air flow formed by the fan 151.

Referring to FIG. 4, when the fan 151 disposed above the heat exchanger 15 is rotated, side ends of the fan 151 may define predetermined rotation regions 153. The rotation region 153 may be understood as a virtual region (area) corresponding to a rotation radius of the fan 151.

The rotation region 153 may be understood as a region included in a sectional area in a horizontal direction of the inner region 130, i.e., the hexagonal area of FIG. 4. That is, the rotation region 153 is less than the hexagonal area.

Also, the rotation region has a diameter D corresponding to the longest distance defined between at least portion of the first heat exchange part 110 and at least portion of the second heat exchange part 120. That is to say, as shown in FIG. 4, two points 153 a and 153 b on a circumference defining the diameter D may be defined at the first heat exchange part 110 and the second heat exchange part 120, respectively.

According to the above-described structure, the external air may smoothly flow by a driving force of the fan 151.

Also, since the fan and the heat exchanger are independently provided as one assembly, the normal operating fan and the heat exchanger is not affected by the broken fan even though one fan of the plurality of fans is broken down.

Hereinafter, a description will be made according to a second embodiment. Since the current embodiment is the same as the first embodiment except for a portion of the heat exchanger in structure, different parts between the first and second embodiments will be described principally, and descriptions of the same parts will be denoted from the descriptions and reference numerals of the first embodiment.

FIG. 6 is a plan view illustrating a set of a fan and heat exchanger according to a second embodiment.

Referring to FIG. 6, an air-cooling heat exchanger 15 according to the current embodiment has a structure in which main pipes and return bands are coupled to each other to realize a refrigerant pipe and the refrigerant pipe passes through a plurality of cooling fins, like the structure of the foregoing embodiment.

However, unlike the structure in which the air-cooled heat exchanger includes the first and second heat exchange parts 110 and 120 in the foregoing embodiment, the air-cooled heat exchanger 15 according to the current embodiment has a structure in which a single heat exchanger is bent several times (four times in FIG. 6), and one side thereof end and the other side end are disposed adjacent to each other.

That is to say, a structure in which a pair of symmetric heat exchangers are disposed adjacent to each other to define one polygonal shape is not provided, but a structure in which one heat exchanger is bent several times to define one polygonal shape is provided. That is, the pair of heat exchangers 110 and 120 may be integrated with each other.

Thus, the return band disposed on one side end and the return band disposed on the other side ends are disposed adjacent to and facing each other. Here, the return bands of both side ends are disposed adjacent to and crossing each other at an angle α less than about 180 degrees.

As described above, the heat exchanger 15 is disposed under the fan 151 to define a closed space and extends in a vertical direction. Thus, external air certainly passes through the heat exchanger 15 while flowing into an inner space of the heat exchanger 15 by a driving force of the fan 151. Therefore, a heat exchange area may increase.

INDUSTRIAL APPLICABILITY

In the air conditioning system according to the embodiments, even though one of the plurality of fan assemblies installed in the heat exchanger is broken down, heat exchange performance in the heat exchange region defined at a side of the other normal operating fan assembly is not affected by the broken fan assembly. 

1. An air conditioner comprising: a mechanical chamber receiving a compressor for compressing a refrigerant and a water-cooled heat exchanger for heat-exchanging water introduced from the outside and flowing along a water pipe with the refrigerant; an air-cooled heat exchanger disposed on a top surface of the mechanical chamber, the air-cooled heat exchanger being fluidly connected to the compressor; and a fan disposed above the air-cooled heat exchanger, wherein a refrigerant pipe constituting the air-cooled heat exchanger is bent several times along an outer edge of the fan and has a polygonal pillar shape extending in a vertical direction.
 2. The air conditioner according to claim 1, wherein the air-cooled heat exchanger comprises: a plurality of main pipes vertically spaced from each other, the plurality of main pipes being bent several times along the outer edge of the fan; and return bands disposed on both side ends of the heat exchanger, the return bands connecting ends of the vertically adjacent main pipes to each other.
 3. The air conditioner according to claim 1, wherein the plurality of main pipes are bent at least two times or more.
 4. The air conditioner according to claim 2, wherein a horizontal section of the air-cooled heat exchanger defines a polygonal plane having a plurality of lines crossing each other at a preset angle, and each of the main pipes is bent by the number of angles on the polygonal plane to allow the return bands disposed on both side ends of the heat exchanger to face each other.
 5. The air conditioner according to claim 2, wherein the present angle is less than about 180 degrees.
 6. The air conditioner according to claim 4, wherein the heat exchanger comprises a first heat exchange part and a second heat exchange part which are symmetric with respect to each other, and the return bands disposed on both side ends of the first heat exchange part are disposed adjacent to the return bands disposed on both side ends of the second heat exchange part to define the polygonal plane.
 7. The air conditioner according to claim 6, wherein the return bands disposed on both side ends of the first heat exchange part and the return bands disposed on both side ends of the second heat exchange part contact each other.
 8. The air conditioner according to claim 6, wherein the first heat exchange part and the second heat exchange part are integrated with each other.
 9. The air conditioner according to claim 6, wherein, when the fan is rotated, a rotation region defined by a side end of the fan is defined, and an inner region of the polygonal plane comprises the rotation region.
 10. The air conditioner according to claim 9, wherein the rotation region has a diameter corresponding to the longest distance between the first heat exchange part and the second heat exchange part.
 11. An air conditioner comprising: a mechanical chamber receiving a compressor for compressing a refrigerant and a water-cooled heat exchanger for heat-exchanging water introduced from the outside and flowing along a water pipe with the refrigerant; an air-cooled heat exchanger disposed on a top surface of the mechanical chamber, the air-cooled heat exchanger comprising a plurality of heat exchange parts; and a fan disposed above the air-cooled heat exchanger, wherein the plurality of heat exchange parts comprise: a first heat exchange part comprising one bent part; and a second heat exchange part coupled to the first heat exchange part, the second heat exchange part comprising the other bent part, wherein the air-cooled heat exchanger has a polygonal box shape due to the coupling of the first heat exchange part and the second heat exchange part.
 12. The air conditioner according to claim 11, wherein the polygonal box shape is a hexagonal box shape.
 13. The air conditioner according to claim 11, wherein the first and second heat exchange parts define a closed space which is not opened in side directions.
 14. The air conditioner according to claim 13, wherein the first heat exchange part and the second heat exchange part are integrated with each other.
 15. The air conditioner according to claim 11, wherein the fan defines a rotation region corresponding to a rotation radius, and two points defining the rotation region on a circumference are defined at the first heat exchange part and the second heat exchange part.
 16. The air conditioner according to claim 11, wherein the air-cooled heat exchanger comprises: a plurality of main pipes vertically spaced from each other, the plurality of main pipes being bent several times along the outer edge of the fan; and return bands disposed on both side ends of the heat exchanger, the return bands connecting ends of the vertically adjacent main pipes to each other. 